Roll with means for removing longitudinal curvature



J. D. ROBERTSON 3,328,866

2 Sheets-Sheet 2 m .DE

rNvENToR. JOHN D. ROBERTSON July 4, 1967 ROLL WITH MEANS FOR REMOVING LONGITUDINAL CURVATURE Filed July 19, 1965 IIA/1145145141559 r United States Patent O 3,328,866 ROLL WITH MEANS FUR REMOVING LONGTUDINAL CURVATURE John D. Robertson, Taunton, Mass., assignor to Mount Hope Machinery Company, Taunton, Mass., a corporation of Massachusetts Filed July 19, 1965, Ser. No. 473,134 15 Claims. (Cl. 29-116) ABSTRACT F THE DISCLOSURE A sheet-supporting roll having means for straightening against curvature or sag. A sleeve is rotatably mounted by a series of spools and bearings on a tubular support, which has at least three internal abutments spaced longitudinally. At least two tension rods extend from an intermediate abutment to abutments at each end of the support, and lie in a plane of curvature of the roll. These rods are tensioned to straighten the ends of the roll individually. The minimum effective number of rods is two less, and of abutments one less, than the number of bearings used, so that all bearings can be aligned correctly to straighten the sleeve.

This invention relates in general to sheet-supporting rolls. The present invention finds particular utility in table rolls of great length, such as are employed in forming the wider webs of paper in Fourdrinier machines, but its use is not limited to rolls of particular lengths.

In the manufacture of paper, as by a Fourdrinier paper machine, a thin suspension of ber in water is deposited on a broad moving belt of line mesh wire screen. The wire is supported for longitudinal movement by a series of transverse table rolls which must be rigid to support their own weight plus the weight of the wire and the paper 'stock without sagging, and have therefore in the past conventionally been given a large diameter (16 inches, for example). In practice, several problems are created by the use of supporting rolls of larger diameter. These problems can be reduced by using table rolls of relatively small diameter to support the wire; but if such table rolls sagged to any appreciable extent, the wire would assume a certain transverse concavity and the watery pulp would tend to run towards the center line instead of remaining evenly distributed over the wire. This would result in the production of paper of nonuniform thickness. My prior U.S. Patent No. 3,094,771, issued June 25, 1963, entitled Table Roll with Means for Removing Longitudinal Curvature, and assigned to the assignee of this application, was directed to the straightening of such rolls.

In the aforementioned patent, a table roll is described which has adjustable means for removing transverse dellection or curvature induced in the roll by its own weight and by the load carried on the roll, and by departure of the axle from a straight configuration occasioned by manufacturing error. The roll described comprises a stationary support of longitudinally-uniform cross-section, preferably formed as a hollow cylinder, which is mounted at its ends in a horizontal attitude to support -an annular sleeve rotatably thereon. A tension rod extends longitudinally through the support eccentrically of a longitudinal axis thereof, and has means for applying an adjustable compression to the support to remove any longitudinal curvature therefrom. The sleeve is mounted upon a multiplicity of annular spools each supported by a bearing assembly on the tubular support. In order to correct deflection of the sleeve caused by manufacturing error as well as the weight of the roll and its load, it is necessary to locate an approximate principal plane of 3,328,866 Patented July 4, 1967 the curvature defined by the centers of all of the bearings of the spools; to position the support with this plane of curvature extending vertically; and to locate the tension rod below the -axis of the support in this plane. In this manner, the deflection or sag lies substantially in a common vertical plane, so that it may be corrected by the tension rod.

In actual practice, all of the centers of the various bearings will not lie exactly in a common plane of support curvature, due to unavoidable manufacturing errors in the locations of the bearing seats on the support member, with the result that the correction applied by the tension rod is not absolutely complete, although it does provide a substantial straightening of the support. In applications in which high rotational speeds are encountered, and in which long rolls are employed, such as in Fourdrinier paper-making machines, even a minor misalignment of the various bearings and spools may result in substantial vibration and binding of the roll. In extreme cases, stress concentrations in the sleeve at the gaps between adjacent spools may rupture a relatively brittle and rigid sleeve material, such as fiberglass or hard rubber.

A partial solution to this difficulty was presented in U.S. Patent No. 3,099,072, to John D. Robertson et al., entitled Table Roll With Means for Removing Longitudinal Curvature, issued July 30, 1963, and also assigned to the assignee of this application. That invention resolved the difculty for a roll having two spools supported on three bearings, one of which is shared by both spools. The arrangement of two spools upon only three bearings causes the location of the major plane of curvature, dened by the curved axis connecting the centers of the bearings, to be precisely determined by only three points. Curvature of the support intermediate these three points does not affect the true axial alignment of the axis of rotation of the sleeve. That solution, however, is not applicable to rolls which have a larger number of spools and bearings.

As the length of the roll is increased, the amount of sag in the two individual spools themselves becomes progressively more serious, and there is a limit to the amount of sag that can be tolerated. An increase in the number of spools and bearings is then necessary, so that the length of each spool is reduced enough to hold its sag to an acceptable value.

It is the primary object of the present invention to provide an improved roll, of a type having a multiplicity of spools and bearings, with means for removing longitudinal curvature induced by the weight of the roll and a supported load. It is a further object to more effectively remove longitudinal curvature from a multiple-spool table roll of relatively great length and small diameter.

Another object of this invention is to provide an improved multiple-spool roll having means for eliminating longitudinal curvature therefrom, which roll at the same time -retains maximum rigidity for a given weight and diameter. Further objects and advantages of the invention will become apparent as the following description proceeds.

The invention may be carried out in a roll having an elongated tubular axle or support, and an outer annular sleeve rotatably mounted on the axle by means of a multiplicity of annular spools and bearings. It is preferred to mount each spool on a pair of bearings at its ends, with adjacent spools sharing a bearing in common. It can be stated in general that if there are n spools, there must be n+1 bearings; to align these bearings requires n-l separate adjustments of axle deflection. According to the invention, the axle is effectively subdivided to isolate sections of the axle each supporting a group of one or two bearings, by means of one ,or more intermediate abutments, welded internally of the axle at appropriate locations along its length. A plurality of tension rods extend from end abutments of the axle, each to grip one of the intermediate abutments. By tensioning these rods, the various sections of the axle can be given different upwardly-convex curvatures when the roll is unloaded, so that the local isolated groups of bearings will be aligned individually with one another, and thus with the longitudinal centerline of the laxle, when the working load is applied to the roll. Appropriate relative tensioning of the various tension rods, with the working load applied, serves to bring the centers of all of the bearings into comformity with one another, so that the multiplicity of spools are commonly aligned.

Several alternative structures may be employed carrying out the invention. In the simplest form, having three spools supported on four bearings, the axle is provided with a single centrally-located intermediate abutment. A unitary tension rod is welded to the intermediate abutment and extends through either end of the axle; The intermediate abutment is welded to the axle following assembly. The intermediate abutment serves to effectively isolate the tension -applied to either end of the rod by nuts threaded thereon, although some degree of interaction remains, so that different degrees of curva-ture may be applied to opposite ends of the roll, as required. The centers of the end-most bearings are taken as reference points to establish the desired straight line, and each of the inner bearings is individually brought into the desired position with respect to this line.

In another form having four or more spools, two or more intermediate abutments are affixed at spaced intervals within the axle; of these, the endmost pair cooperates with tension rods extending to the abutments at the outer ends of the roll, to straighten only hose axle sections lying outwardly `of this pair. Each of the more central sections of the axle is straightened by means of a corresponding number of additional tension rods. Each of these additional rods extends from an intermediate abutment through the length of the corresponding section Whose curvature it is to correct, and thence through the intervening abutments to an end of the roll. At least one of the endmost tension rods may be a hollow tube or cartridge, receiving one of the additional rods in telescoped relation. The cartridge may be placed in tension, in which case both the tension in the cartridge and that in the rod extending through it will be applied to compress the endmost section of the axle. However, a `greater bending movement is required for straightening central sections than end ones. This difiiculty may be corrected by permanently deforming the central sections with an upward bend. Alternatively, the cartridge may be subjected to compression, to reduce the bending moment applied -to the endmost section by the interior rod to an appropriate value.

The tension loads on all sections should act substantially in a common plane passing through the roll axis, and this is facilitated by a telescoping arrangement. However, this result may also be obtained by using a pair of tension rods for a given section, symmetrically spaced on either side of the selected plane; and these may also apply diiferent degrees of tension to correct residual curvature due to manufacturing tolerances in a plane perpendicular to the principal, vertical plane of curvature.

The rods are generally straight, in which case they extend parallel to the roll axis, and are symmetrically spaced about a vertical axial plane. However, the rods may alternatively be inclined to the roll 4axis in the vertical plane, to form an adjustable truss.

Further objects and advantages of the invention will be apparent from the following detailed description of preferred embodiments of the invention, referring to the accompanying drawing, in which:

FIGURE l is a longitudinal elevation in section of a rst form of roll according to the invention, foreshortened in longitudinal scale for xgreater clarity;

FIGURE 2 is a fragmentary longitudinal elevation in section of a second embodiment of the invention;

FIGURE 3 is a section-al plan view of the axle of the roll of FIGURE 2, showing its interior parts;

FIGURE 4 is a right-hand end view of the roll of FIGURE 2;

FIGURE 5 is a left-hand end view of the same roll;

FIGURE 6 is a longitudinal elevation in section of a modified arrangement of the interior parts of the axle;

FIGURE 7 is a longitudinal sectional View of another modication of the interior parts; and

FIGURE 8 is a sectional view in elevation of a further embodiment.

Referring to FIGUR-E 1, a first form of the improved roll is shown with an exaggerated upwardly convex curvature which occurs after adjustment and upon removal of the load which the roll is designed to carry. The axle or tubular support 12 comprises a tubular cylinder of uniform wall thickness, preferably free of longitudinal discontinuities. This conguration of the axle affords a maximum of rigidity against transverse deflection due to changes in load, for a given diameter and weight. The mass of the axle is of great importance in view of the fact that the roll is commonly operated above a critical rotational speed, and mass rather than rigidity limits the amplitude of vibration of the roll at these speeds. And because of the high speed of rotation involved as well as the great length of table rolls, they must be dynamically Well-balanced.

Transverse deilection or sag of a roll is induced by its own weight and that of loads supported thereon. Furthermore, available manufacturing methods leave some residual longitudinal curvature in the support. For the elimination of this longitudinal curvature, according to the invention, various isolated sections of the axle are bowed upwardly, parallel to a common plane, each with an individual and adjustable longitudinal curvature; and the axle is so oriented in its supports that the plane of curvature lies parallel to the resultant downward force which tends to produce transverse deilection. The resultant force includes the cumulative components of the Weight of the axle itself, and the dynamic and static loads of the wire and paper supported on the roll. In the plane of curvature, the convex side of the bow faces upwardly as shown in the drawing. The local curvatures are to be adjusted so that elastic deflections of each isolated section of the rol-l, induced by the local resultant force, cause the roll to assume a longitudinally straight and uncurved configuration in actual use. v

The support 12, in this embodiment, carries three spools, including a pair of end spools 18 and a central spool 14, mounted in end-to-end relation. Each spool is rotatably mounted on a pair of the ball bearings 161, 162, 163 and 164, so that each of the more central bearings supports two adjacent spools. A surface sleeve 24, which is preferably of a corrosion-resistant, hard, and moderately resilient material such as berglass or hard rubber, `is engaged circumferentially about all of the spools, connecting them for rotation in unison with the sleeve about the support 12. A pair of annular caps 26 are fastened to the outermost ones of the spools Iby any suitable means (not shown); if desired, means may be provided to form a water-tight rotating seal with the support to protect the enclosed ball bearing units.

The end portions of the support 12 extend through and are supported by spherical bearing elements '28 which are mounted for relative canting movement of the support within bearing members 30l on fixed supports 32. When the center of the roll is deflected upwardly in an unloaded condition, as shown on an exaggerated scale in FIGURE 1, the end portions cant downwardly slightly with respect to the longitudinal axis of the roll.v IlQVifever, the deflection is very slight, and is removed by adjustable means of the invention during actual use of the roll, under a load; plain cylindrical supports may therefore be substituted if desired.

Extending lengthwise through the support 12 is a tension rod 34 having threaded end portions 36. Stout end abutments 37 are received in opposite ends of the support, and are provided with aligned openings to receive the end portions of the rod 34. It will be noted that these openings are formed eccentrically in the abutments so that the rod will lbe arranged parallel to, but spaced vertically beneath, the longitudinal axis of the roll. A pair of nuts 40 engage the ends of the rod and are tensioned against the abutments. By tightening the nuts 40, the rod 34 may be subjected to increasing tension, and the support may be placed under an eccentric longitudinal compressive force. This force is used to remove longitudinal curvature from the roll.

The means thus far described are substantially in accordance with the disclosure of the aforementioned U.S. Patent No. 3,099,072; however, under those teachings, the tension rod 34 would extend freely and without additional restraint between the end abutments 37. Since more than three bearings are used in the illustrated roll, it would not be possible to align the full set of them with the single adjustment available.

According to the present improvement, the axle is subdivided into a series of isolated sections, each of which supports one or two bearings. The sections are dened, and substantially isolated, by means of intermediate abutments spaced axially between the end abutments. Each intermediate abutment is afiixed in the interior of the tubular axle, and serves to translate the tension of an associated rod into a bending moment applied primarily to a corresponding section of -the axle. The tension applied to each section is adjusted to align the bearings mounted on that section with one another, and with a common reference axis. The reference axis may be established by the centers of the two endmost bearings 161 and 164; if the bearing 162 is aligned with 161 and 164 and the bearing 163 independently aligned with 161 and 164, all of the bearings are coaxial.

In the embodiment of FIGURE 1, in which four bearings and three spools are utilized, a single intermediate abutment 42 is centrally located in the axle. A common tension rod 34 passes eccentrically through this abutment, n alignment with its mounting in the end abutments 37, and is fillet-welded to the abutment as shown at 46. The abutment is then plug welded to axle 12 through holes in the same. This arrangement serves to isolate the opposite ends of the tension rod so that different degrees of tension may be applied to either end by the corresponding nuts 40. In practice, the tension rod 34 and the abutment 42 are welded together prior to their assembly with the axle 12, and the welds 44 are made after drilling circumferentially spaced holes through the Wall 0f the axle.

Before attaching the end abutments 37 to the axle, the latter is inspected to determine the principal plane of the curvature of the longitudinal axis, resulting from its manufacturing tolerances. The residual curvatures of each end will generally lie substantially in a common plane, though they maybe of differing magnitude. The abutments 37 are then aligned with their holes in the plane of residual axle curvature.

The normal load is then applied, and the nuts 40 are individually tightened until the spools are brought into an axially-aligned condition in the vertical plane. The centers of the bearings 161 and 164 may Ibe regarded as defining a reference axis, with which the bearings 162 and 163 are individually aligned. Unequal degrees of tension will ordinarily be needed in the opposite ends of the rod to achieve this result. Should the working load be altered for any reason, the tension may be readjusted as necessary to restore the axle to a straight condition. It

will be apparent that when the normal load is removed after the adjustment has been made, the roll will assume a slight upward deflection, as illustrated on an exaggerated scale in FIGURE 1.

An embodiment in which there are four spools and ve bearings, requiring that the axle be separated into three isolated sections to aiford three adjustments, is shown in FIGURES 2-5. Parts similar to those of the foregoing embodiment are similarly numbered. A pair of intermediate abutments 48, 50 are spaced longitudinally within the axle, and welded in place. The central section of the axle defined between these abutments is subjected to compression by an elongated tension rod 52, having a head 54 at one end bearing against the abutment 48. This rod passes freely through the abutment 50 to one of the end abutments 37, where it is engaged `by a nut 40.

The rod 52 occupies the vertical axial plane through the right hand section of the roll. The end-most sections are provided with pairs of tension rods 56 and 58, respectively, which are symmetrically spaced on either side of the vertical axial plane. The pair 56 has its heads 60 bearing on the abutment 48, and extends through the left-hand end abutment for receiving a pair of nuts 40, while the pair 58 similarly has its heads 62 bearing against the abutment 50, and extends through the right-hand end abutment 37. The tension of each of these pairs acts cumulatively to compress a corresponding section of the rod with a component in the vertical plane, and differentially to compress the section in the horizontal axial plane. Therefore, these pairs may be adjusted not only to secure straightening of the corresponding axle sections in the vertical plane, but also to correct any residual curvature in the horizontal plane.

In an alternative embodiment shown in FIGURE 6, tension is applied to an end section of the axle by a tubular cartridge 66, which receives a tension rod 78 in telescoping relation. The cartridge has a head 68 engaging an intermediate abutment 70, extends freely through an opening 72 in an end abutment 74, and has a nut 76 threaded on its protruding end. The tension rod 78 extends interiorly through the tension rod 66, and thence through a central section of the axle to a further intermediate abutment 80, having a head 82 engaging this abutment. A nut 84 is threaded on the protruding end of the rod 78, acting against the rod 66 through a Washer 86. It is thus possible to align two rods on a common axis in telescoping relation; and additional tubular cartridges may be received coaxially with the cartridge 66 to accommodate further central sections when necessary.

It should be noted that the total tension in all of the rods 52 and 58 in FIGURE 2, or the total tension in the rod 78 and cartridge 66 in FIGURE 6, acts on the righthand end section of the axle. However the largest bending moment is required in the central section, This problem can be resolved by permanently deforming the central section with `an upward curvature or pre-bow, so that this section will require Iless bending moment than the end sections.

An alternative solution is to utilize the -cartridge as a compression member, as shown in FIGURE 7. Parts similar to those in the embodiment of FIGURE 6 are similarly numbered. vIn this case, a tubular cartridge or rod means is a compression member which serves to offset partially the bending moment applied to the end-most section of the axle by .the tension rod 78. The cartridge abuts against the intermediate abutment 70, and is threaded in the end abutment 74, having an integral head 92 for adjusting its compression loading. The tensioning nut 84 bears directly on this head. The bending moment applied to the endmost section lying between the abutments 70 and 74, is a function of the difference between the loadings of the rod 78 and cartridge 90, while the bending moment applied to an intermediate section by the rod 78 is substantially a function of the loading in this rod alone.

Thus, the greater bending moment required in the intermediate section can be accommodated without permanent deformation of the intermediate section into `a prebow to assist the tension rod 78.

Still another embodiment is shown in FIGURE 8, in which parts similar to those of the foregoing embodiments are again similarly numbered. A pair of tension rods 102, 104 extend the full length of the axle 12; each passes freely through an opening 108 in one of the intermediate abutments 96 or 98, and is aixed to the other intermediate abutments by any suitable means, such as a weld 106. Each rod is thus effectively divided to form two tension rod means, for applying an independent bending moment to each portion of the axle subdivided by the intermediate abutment to which that rod is afxed. The rods are parallel to a substantially vertical axial plane, but are inclined to the roll as shown, thus forming an adjustable truss structure. In this case the loadings in each rod aifect every section of the axle. A greater bending moment can be applied to the central axle section, by applying a lesser tension to those portions of each rod which extend directly from an end abutment to a weld point at an adjacent intermediate abutment (eg. the right han-d segment of rod 104 as seen in the drawing), and a greater tension to the longer segment of each rod which passes through an opening 108 and across two adjacent sections.

In general, it should be understood that the principle of the invention can be applied to rolls having still more spools than those shown in the illustrated embodiments; it is only necessary that for n bearings or support points, at least n--Z rod means be provided for independent correction of axle deflection. Preferably, each spool is supported at two points by bearings of which one or both is shared in common with an axially-adjacent 'spool or spools, so that there are n-l spools. Also, one integral rod may form two rod means whose loadings are independent, as in FIGURES l and 8.

The present invention is also applicable in its broader aspects to rolls such as are described in my copending application entitled Fluid Bearing Table Roll, U.S. patent application Ser. No. 505,101 tiled Oct. 15, 1965 which have no spools or bearings, but instead support the rotating sleeve directly on the support by means of a iiuid bearing.

It is to be understood that the foregoing description of preferred embodiments of the invention is given for purposes of illustration, and that various changes and modification may be made therein Without departing from the true spirit and scope of the invention, which I therefore intend to dene in the appended claims without limitation tothe details of the foregoing embodiments.

What I claim is:

1. A roll comprising an elongated tubular support of substantially symmetrical cross-section, said support being subject to externally-applied forces whose resultant acts to produce a bending moment in an axial plane tending to cause longitudinal curvature thereof in said plane; a sleeve, means supporting said sleeve against transverse sagging and mounting said sleeve for rotation about said support at more than three axially spaced points; a pair of abutments engaged in the opposite ends of said support; at least one intermediate abutment secured within said support in axially spaced relation to said end abutments to define and isolate a plurality of individual sections of said support; at least two tension rod means each extending longitudinally interiorly of said support from said intermediate abutment through a corresponding one of said end abutments, said rod means being parallel to `and symmetrically spaced about said axial plane of curvature; means for adjustably tensioning said rod means individually; such that the individual compression reactions to the tension in each rod means, are applied each through a pair of said abutments comprising one of said end abutments and said intermediate abutment, to eccentrically compress said individual sections of said support; said rod means being -arranged to apply said reactions to subject said support to a bending moment in said axial plane opposing the bending moment applied by said resultant; whereby longitudinal curvature of said roll may be eliminated by tensioning the various rod means to align those of said points lying within each of said support sections with the major axis of said support.

2. A roll as recited in claim 1, in which said two tension rod means are formed by a unitary rod extending through the length of said support and through said intermediate abutment, being aflixed to said intermediate abutment.

3. A rol-l comprising an elongated tubular support of substantially symmetrical cross-section, said support being subject to externally-applied forces which produce a bending moment in an axial plane tending to cause longitudinal curvature thereof in said plane; a sleeve; a multiplicity of spools received in axially-spaced relation Within said sleeve for supporting said sleeve against transverse sagging; a multiplicity of bearings spaced axially along said support, and mounting said spools rotatably on said support and each providing la support point for a least I one of said spools; a pair of abutment means engaged in the opposite ends of said support; intermediate abutment means secured within said support in axially-spaced relation to said end abutment means; a plurality of tension rod means extending longitudinally interiorly of said support from said intermediate abutment means through each of -said end abutment means, said rod means being parallel to and symmetrically spaced about said plane of curvature, and eccentric to the longitudinal axis of said support, the number of said rod means being two less than the number of said bearing; and means engaging said rod means for adjustably tensioning said rod means individually; such that the individual compressional reaction-s to the tension in each rod means, are applied each through a pair of tension in each rod means, are applied each through a pair said abutment means comprising one of said end abutment means and said intermediate abutment means to eccentrically compress individual sections of said support, extending between and isolated by the corresponding pair of abutment means; said rod means being arranged to apply said reactions to subject said support to a bending moment in said axial plane opposing the bending moment applied by said resultant; whereby longitudinal curvature 1of said roll may be eliminated by tensioning the various rod means to align the centers of those bearings mounted on each support section with one another, and with the major axis of said support.

4. A roll as recited in claim 3, in which the minimum number of said bearings is one greater than the number of said spools.

5. A roll as recited in claim 4, in which each of all but two of said bearings supports axially-adjacent pairs of said spools in common.

6. A roll as recited in claim 3, in which the minimum number of said intermediate abutment means is three less than the number of said bearin gs.

7. A roll as recited in claim 3, in which the maximum number of said bearings is two more than the number of said rod means.

8. A roll comprising an elongated tubular support of substantially symmetrical cross-Section, said support being subject to externally-applied forces whose resultant acts to .produce a bending moment in an axial plane tending to cause longitudinal curvature thereof in said plane; a sleeve; means supporting said sleeve against transverse sagging and mounting said sleeve for rotation about said support at more than three axially spaced support points; end abutment; means engaged in the opposite ends of said support; intermediate abutment means secured within said support in axially-spaced relation to said end abutments to dene and isolate va plurality of individual sections of said support; a plurality of rod means each extending longitudinally interiorly of said support from one of said intermediate .abutment means, through one -of said sections, and through any intervening ones of said intermediate abutment means to one of said end abutment means, said rod means being parallel to and symmetrically spaced about said plane of curvature, and arranged to apply bending moments through said abutment means to said support in said axial plane in a sense to offset bending moments applied by said resultant; the number of said rod means being two less than the number of said support points; means for applying adjustable longitudinal loadings to said rod means individually; such that the loadings in each rod means are applied each through a pair of said abutment means comprising one of said end abutment means and one of said intermediate abutment means, to eccentrica-Hy compress one of said individual sections of said support; whereby longitudinal curvature of said roll may be eliminated by loading the various rod means to align those of said support points lying within each of said support sections with one another, and with the major axis of said support.

9. A roll as recited in claim 8, in which at least one of said rod means extends from one of said end abutment means through an endmost one of said sections adjacent to the end of said support, and thence through a lrst intermediate abutment means to a second intermediate abutment means, for applying compression to an intermediate one of said sections dened between said rst and second intermediate abutment means; another of said rod means extending from said one end abutment means to said rst intermediate abutment means, whereby the loadings applied to said one and said other rod means are applied to said endmost section, and the loading applied to said one rod means is applied to said intermediate section.

10. A -roll as recited in claim 9 in which said other rod means comprises a tubular cartridge receiving said one rod means therethrough, and has opposite ends thereof engaging said one end abutment means and said first intermediate abutment means.

11. A roll as recited in claim 9, in which said one rod means comprises a tension member and said other rod means comprises a compression member, land said loading means are constructed yand arranged to apply a load in tension to said one rod means and a load in compression to said other rod means; whereby the bending -moment applied to said endmost section is a function of the diierence between the loadings in said one and said other rod means, while the bending moment applied to said intermediate section is a function of the loading applied to said one rod means.

12. A roll as recited in claim 9, in which said one and said other rod means comprise tension members and said loading means are constructed and arranged to load said one and said other rod means in tension; whereby the bending moment applied to said endmost section is a function of the sum of the loadings applied to said one and said other rod means, and the bending moment applied to said intermediate section is a function of the tension in said one rod means; said intermediate section being permanently deformed with a curvature tending to assist the bending moment applied by said one rod means in opposing longitudinal curvature of said roll induced by a load applied thereto.

13. A roll as recited in claim 9, in which each of said intermediate abutment means is formed with a clearance opening receiving at least one of said rod means freely therethrough; said rod means extending through the full length of said support to engage both of said end abutment means, and each being aiixed to one of said intermediate abutment means other than those through which it is freely received; whereby each rod means is capable of -applying different bending moments to portions of said support subdivided by the abutment means to which that rod means is aixed.

14. A roll as recited in claim 13, in which the portions of each of said rod -means extending to each of said end abutment means from the intermediate abutment means to which that rod means is afxed, lie substantially parallel to said plane of curvature but are inclined to the longitudinal axis of said support, to form an adjustable truss.

15. A roll as recited in claim 8, in which at least one pair of said rods terminates in a common one of said intermediate abutment means for jointly compressing one of said sections, and is spaced symmetrically on either side of said axial plane of curvature, lying in a common plane parallel to said longitudinal axis of said support and normal to said plane of curvature, for removing residual curvature of said one section in said common plane.

References Cited UNITED STATES PATENTS 2,547,975 4/1951 Robertson 26--63 2,952,889 9/1960 Hanssen 29--116 X 3,094,771 6/1963 Robertson 29-116 3,099,072 7/ 1963 Robertson et al. 29-116 BILLY I. WILHITE, Primary Examiner. 

1. A ROLL COMPRISING AN ELONGATED TUBULAR SUPPORT OF SUBSTANTIALLY SYMMETRICAL CROSS-SECTION, SAID SUPPORT BEING SUBJECT TO EXTERNALLY-APPLIED FORCES WHOSE RESULTANT ACTS TO PRODUCE A BENDING MOMENT IN AN AXIAL PLANE TENDING TO CAUSE LONGITUDINAL CURVATURE THEREOF IN SAID PLANE; A SLEEVE, MEANS SUPPORTING SAID SLEEVE AGAINST TRANSVERSE SAGGING AND MOUNTING SAID SLEEVE FOR ROTATION ABOUT SAID SUPPORT AT MORE THAN THREE AXIALLY SPACED POINTS; A PAIR OF ABUTMENTS ENGAGED IN THE OPPOSITE ENDS OF SAID SUPPORT; AT LEAST ONE INTERMEDIATE ABUTMENT SECURED WITHIN SAID SUPPORT IN AXIALLY SPACED RELATION TO SAID END ABUTMENTS TO DEFINE AND ISOLATE A PLURALITY OF INDIVIDUAL SECTIONS OF SAID SUPPORT; AT LEAST TWO TENSION ROD MEANS EACH EXTENDING LONGITUDINALLY INTERIORLY OF SAID SUPPORT FROM SAID INTERMEDIATE ABUTMENT THROUGH A CORRESPONDING ONE OF SAID END ABUTMENTS, SAID ROD MEANS BEING PARALLEL TO AND SYMMETRICALLY SPACED ABOUT SAID AXIAL PLANE OF CURVATURE; MEANS FOR ADJUSTABLY TENSIONING SAID ROD MEANS INDIVIDUALLY; SUCH THAT THE INDIVIDUAL COMPRESSION REACTIONS TO THE TENSION IN EACH ROD MEANS, ARE APPLIED EACH THROUGH A PAIR OF SAID ABUTMENTS COMPRISING ONE OF SAID END ABUTMENTS AND SAID INTERMEDIATE ABUTMENT, TO ECCENTRICALLY COMPRESS SAID INDIVIDUAL SECTION OF SAID SUPPORT; SAID ROD MEANS BEING ARRANGED TO APPLY SAID REACTIONS TO SUBJECT SAID SUPPORT TO A BENDING MOMENT IN SAID AXIAL PLANE OPPOSING THE BENDING MOMENT APPLIED BY SAID RESULTANT; WHEREBY LONGITUDINAL CURVATURE OF SAID ROLL MAY BE ELIMINATED BY TENSIONING THE VARIOUS ROD MEANS TO ALIGN THOSE OF SAID POINTS LYING WITHIN EACH OF SAID SUPPORT SECTIONS WITH THE MAJOR AXIS OF SAID SUPPORT. 